1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device.
2. Description of the Related Art
When copper is applied as a metal line of a semiconductor device, a dual damascene process is generally performed to form a trench and a via hole in a line shape.
FIG. 1 is a sectional view illustrating a method for manufacturing a copper line according to a related art.
Referring to FIG. 1, an insulation layer 12 is formed on a bottom structure 11 where a predetermined process has been performed. Then, the insulation layer 12 is etched by performing a dual damascene process to form a dual damascene pattern 13.
Next, a copper line 14 is formed using electroplating etc. until the dual damascene pattern 13 is filled.
Next, a chemical mechanical polishing (CMP) process is performed to planarize and/or separate adjacent copper line layers 14.
The above process is called a Cu CMP process. After the Cu CMP process, a cleaning process is performed to remove floating or extraneous matter and slurry generated during the CMP process.
However, according to a related art, copper corrosion 15 may form on the copper line layer 14 by photo corrosion or galvanic corrosion after cleaning, or copper remainder 16 may remain on the surface of a wafer after cleaning.
When an intermetal dielectric (IMD) layer is deposited without removing the copper corrosion 15 or the copper remainder 16, adhesion of the subsequently deposited IMD may be weakened. Additionally, copper atoms in the copper remainder 16 may diffuse into the IMD layer, thereby increasing the possibility of causing a short between the copper line layers 14.
Accordingly, the related art process may require an additional cleaning process to remove particles that may not be removed during the cleaning process or that may be generated after the cleaning process. If the IMD layer is deposited when the particles remain, copper may diffuse between the dielectric layers due to an insufficient adhesion.
Especially, because it is difficult to remove certain copper residue such as the copper corrosion generated by photo corrosion or galvanic corrosion and the copper remainder caused by an uneven wafer surface in the related art process, a new cleaning process is in demand.